1. Field of the Invention
The present invention relates to a specimen temperature adjusting apparatus that adjusts the temperature of an observation specimen.
2. Description of the Related Art
In general, specimen observation using a microscope is performed by moving an object lens close to a specimen placed on a microscope stage and magnifying the observation target portion on the specimen. Regarding the objective lens, which is moved close to the specimen, the larger the magnification, the smaller the depth of focus, and the more difficult alignment of the objective lens and observation specimen. Also, even a small change in distance between the objective lens and specimen blurs the observation image. While the apparent positions of the objective lens and observation specimen are very close to each other, the pass-way of their mechanical connection is very long due to the presence of a large number of mechanical components such as a microscope frame, an objective lens moving mechanism, a revolver, and the like. The mechanical components tend to change their sizes depending on a temperature change. During specimen observation, assume that the objective lens has been focused on the observation specimen. Upon the ON/OFF operation of the illumination and the operations of the internal power supply and air-conditioning facilities, when the ambient temperature changes to change the sizes of the mechanical components, the distance between the objective lens and specimen changes. Accordingly, the focal point is shifted readily.
In order to solve this drawback, Jpn. Pat. Appln. KOKAI Publication No. 2001-305432 discloses an apparatus that detects the distance between an objective lens and a specimen stage by a displacement sensor and maintains the distance constant.
Recently, vital specimen observation using a microscope has been performed widely, and a vital specimen must be kept alive on the microscope for a long period of time. In view of this, for example, Jpn. Pat. Appln. KOKAI Publication No. 2003-50358 discloses an apparatus that keeps a vital specimen at a predetermined temperature.